You're not my customer so what phones you decide to buy or not buy is of little consequence to me.
If you actually want help troubleshooting your issues, you'll need to give us some information. What iPhone do you have? What version of iOS? You say you can't use "all of my apps" then you say you can use "some of them". What exactly is happening? What apps can you use? Which ones are a problem? Are they the third party apps? What trouble shooting steps have you taken so far? Have you tried resetting your phone by pressing and holding the Home and power keys until the Apple appears?